Treatment of textile materials containing carbonizable fibres and product thereof



Patented Dec. 1, 1931 UNITED STATES PATENT OFFICE CAMILLE DREYFUS ANDROBERT G. DORT, OF NEW YORK, N. 'Y., AND HERBERT PLATT,

OF CUMBERLAND, MARYLAND, ASSIGNORS TO CELANESE CORPORATION AMERICA, ACORPORATION OF DELAWARE TREATMENT OF TEXTILE MATERIALS CONTAININGCARBONIZABLE FIBRES AND PRODUCT THEREOF No Drawing. Original applicationfiled May 3, 1928, Serial No. 274,956. Divided and this applicationfiled October 26, 1929. Serial No. 402,794.

This invention relates to the treatment of yarns containing vegetablefibres, such as cellulose, that are readily carbonizable by certaincarbonization processes and fibres or threads of a material, such asorganic esters of cellulose, silk or wool that are not readilycarbonizable by such processes, whereby novel effects are obtained.

This application is a division of our prior application 274,956 filedMay 3, 1928.

An object of our invention is to produce novel effects with textilematerials containing mixtures of materials that are readily corbonizableby a given process, and materials that are not readily carbonizable bysuch process by wholly or partially carbonizing the readily carbonizablematerial.

Another object of our invention is to produce novel spun yarn by subjectin a mixed spun yarn containing a readily car onizablefibre, such ascellulose, and short lengths of filaments made of organic derivatives ofcellulose, that are not readily carbonized by the same method, to acarbonizing treatment, either locally or throughout, wherebysatisfactory spun yarn is produced. Other objects of our invention Willappear from the following detailed description.

In accordance with our invention, We treat a spun yarn containing fibresthat are readily carbonizable by the subsequent treatment and threads orfibres that are not readily carbonizable by such treatment with acomposition of matter containing a solution that promotes carbonizationof the readily carbonizable material, and we then subject the yarn toelevated temperature, whereby the readily carbonizable material isremoved or rendered removable while the other material is hardlyaffected at all.

The readily carbonizable fibres employed in our invention are vegetablefibres such as cotton or flax or fibres-of reconstituted cellulose. Theyarns, threads or fibres of material that is not readily carbonized bythe subsequent treatment may comprise animal fibres such at natural silkor wool, but we prefer to employ organic derivatives of cellulose.Examples of organic derivatives of cellulose are organic esters ofcellulose such as cellulose acetate, cellulose formate, cellulosepropionate and cellulose butyrate or cellulose ethers such as methylcellulose, ethyl cellulose and benzyl cellulose.

Any suitable carbonizing agent may be used. Among the carbonizing agentsthat are suitable for use when an organic derivative of cellulose ispresent or when animal fibres are present in the textile materials, aresolutions of aluminum chloride or hydrochloric acid of suitableconcentration; while if animal fibres such as natural silk or wool arethe only carbonization-resistant fibres present, stronger carbonizingagents such as sulphuric acid or the acid sulfates of sodium orpotassium may be employed. The carbonizing solution may be employed assuch, and may be applied to the textile material by dipping, immersion,padding or spraying. On the other hand, the carbonizing solution may beemployed in admixture with a thickening agent such as starch, dextrine,British gum, gum tragacanth, etc. and applied in the form of a pastelocally in any desired pattern, or over the entire surface of the yarn.

After the textile material has been treated with the composition ofmatter containing the carbonizing solution, it is heated to elevatedtemperatures, say 110 C. to 120 C. for a sufiicient period of time tocarbonize the vegetable or cellulosic material, after which thecarbonized material is removed by brushing or washing.

One application of our invention is for the preparation of spunyarns-made of organic derivatives of cellulose. Organic derivatives ofcellulose yarns are made from solu tions of the organic derivatives ofcellulose by extrusion of the solutions through fine orifices and theremoval of the solvent from 3 the filaments thus formed. Since thefilaments are formed continuously, the yarns formed therefrom are ofcontinuous length. Often it is desirable to prepare yarns of thesematerials that comprises short lengths of such filaments or yarns thatare spun together. However, because of the lack of cohesion betweenyarns of cellulose acetate, it is not possible to prepare satisfactoryspun yarns unless fibres of other materials are associated with theshort lengths of the cellulose acetate yarn.

By our invention spun yarns consisting wholly of cellulose acetatestaples may be prepared by spinning a mixture of the short celluloseacetate staples and vegetable fibres such as cotton,reconstitutedcellulose, etc., to form a yarn, and then subjecting the mixed yarn to acarbonization treatment as herein described to remove the vegetablefibres, thus leaving a spun yarn consisting Wholly of short staples ofcellulose acetate fibres. Obviously some animal fibres, such as silk orwool, may be mixed with the cellulose acetate and cotton fibres, andsince they are unaffected by the carbonization treatment, a yarncomprising cellulose acetate fibres and animal fibres will remain.

Obviously the textile material may be dyed, bleached, etc., eitherbefore or after the carbonization treatment, in any suitable manner asis well understood in the art. If it is desired to prevent delusteringof the yarn containing the organic derivatives of cellulose,deluster-preventing salts such as Glaubers salt or any of thedeluster-preventing salts mentioned in U. S. Patent No.

' to the treating solution.

In order further to illustrate our invention, the following detaileddescription of two examples are given.

Ewample A spun yarn containing short filaments of cellulose acetate.which are resistant to carbonization, and of cheap cotton. or reconstituted cellulose fibre. which is easily .carbonized. is selected.This yarn is immersed in the form of hanks in a bath contaming asolution of aluminum chloride of 6 to 13 Be. at ordinary roomtemperature.

The excess of aluminum chloride solution is then removed by pressing.squeezing. or bydroextraction. etc.. and the yarn is then placed in acarbonized dryer and treated at a temperature of 110 to 115 C. for from1 to 1 ,4; hours. The yarn is then removed from the drver and is brushedor washed, whereupon the carbonized cotton is removed. Since thecellulose acetate yarn is unaffected, a spun yarn consisting wholly ofcellulose acetate fibres is produced.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of this invention.

Having described our invention, what we claim and desire to secure byLetters Patent 1s:

1. The processof producing spun yarn containing organic derivatives ofcellulose, comprising spinning short lengths of organic derivatives ofcellulose yarn with vegetable fibres and then carbonizing the vege tablefibres out of the mixed spun yarn.

2. The process of producing spun yarn containing cellulose acetate,comprising spinning short lengths of cellulose acetate yarn withvegetable fibres and then carbon-

